Magnetic tape press

ABSTRACT

A press for punching minute toroids for magnetic core memories from a ferrite web member includes a central die plate disposed between an upper guide plate and a lower guide plate. The ferrite web member is advanced through a slot between the central die plate and the lower guide plate and stamped toroids are ejected through a slot in the upper guide plate adjacent the central die plate. A number of holes extending through the three plates at an acute angle with respect to the direction of web member motion but normal to the plane of the web member each receive a set of ganged punches. Each set includes an upper core rod inserted through the upper guide plate for punching the central disk of the toroid, a lower punch having an outside diameter for punching the outside diameter of a toroid and a central bore coaxially aligned with the core rod for receiving the core rod. The central disks are forced through the central bore in the lower punch and maintained segregated from the toroids.

United States Patent [191 1 MAGNETTC TAPE amass [75] lnventor: lilo Bin 1m, Northridge, Calif.

[73] Assignee: Ampex Corporation, Redwood City,

Calif.

[22] Filed: Nov. 18, 11971 [21] App]. No.: 208,001]

Primary Examiner-J. M. Meister Att0rrzeyRobert G. Clay MECHANISM CONTROL [57] ABSTRACT A press for punching minute toroids tor magnetic core memories from a ferrite web member includes a central die plate disposed between an upper guide plate and a lower guide plate. The ferrite web member is advanced through a slot between the central die plate and the lower guide plate and stamped toroids are ejected through a slot in the upper guide plate adjacent the central die plate. A number of holes extending through the three plates at an acute angle with respect to the direction of web member motion but normal to the plane of the web member each receive a set of ganged punches. Each set includes an upper core rod inserted through the upper guide plate for punching the central disk of the toroid, a lower punch having an outside diameter for punching the outside diameter of a toroid and a central core coaxially aligned with the core rod for receiving the core rodv The central disks are forced through the central bore in the lower punch and maintained segregated from the toroidsi 11 Claims, 13 Brawing Figures MAGNETIC TAPE PRESS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to punch presses and more particularly presses for stamping magnetic cores from ferrite tape.

2. History of the Prior Art Magnetic toroidal cores for computer memories are most commonly manufactured by pressing ferrite powder into the desired shape. However, this process has certain disadvantages and problems under particular conditions. One is that the ferrite powder is quite abrasive and .equires relatively strong forces to be compacted into the desired shape. As a result, the relatively expensive dies used for pressing sustain a great deal of wear and must be sharpened or replaced at frequent intervals.

Another problem arises from a trend toward increasingly smaller core sizes, such as 17 mil diameters and less. As the difference between the inside and outside diameters of the cores decreases in these very small size ranges, the radial width of the core approaches the size of the ferrite particles therein and it becomes increasingly difficult to distribute the ferrite particles uniformly prior to compaction. As a result, the pressed cores tend to have structural flaws and undesirable magnetic characteristics.

Some of these problems have been reduced by combining the ferrite particles with a flexible binder and rolling them into a web member or tape. The toroidal cores are then stamped from the tape and heat treated to obtain the desired properties. With this process there is no need to attain a uniform powder density within a tiny stamping die. Furthermore, because the force required to shear the ferrite tape is much less than that needed to compact the ferrite powder, the life span of a punch or die is greatly increased.

Among the known arrangements of punch presses for small magnetic cores are one which utilizes a two-step operation, thereby presenting alignment problems, one which fails to separate the cores from their centers, and

one double-punch arrangement which utilizes upper and lower punches positioned on opposite sides of a die plate. Although the latter arrangement is preferred, it suffers from certain disadvantages.

In the double-punch arrangement, the punch pairs are ganged along a line perpendicular to tape motion with the upper punches held by one die holder and the lower punches held by another die holder. However, as core size decreases, greater manufacturing precision is required for operable alignment of the upper and lower punches and the die plate. As core sizes continue to decrease to an outer diameter of 17 mils and below, punches become more fragile, tolerances become more precise and manufacturing requirements become inordinately expensive or even impossible to meet.

Additionally, manufacturing precision and costs increase as the distance between adjacent pairs of punches decreases. Thus, when pressing small cores, the punches must either be located close together at increased cost, or spaced apart, thereby wasting ferrite tape.

SUMMARY OF THE INVENTION A press in accordance with the invention for stamping toroidal cores from ferrite tape stamps both the inside and outside diameters in a single punching cycle which separates the centers from the toroidal rings. As the tape is passed through an internal tape guide aperture between a die plate having die holes therein and a set of outer punches having a central bore, a set of core rods extends through the die holes to meet the tape. The outer punches are then extended to engage the core rods in mating relationship within a punching zone. As the outer punches extend the inner diameters are sheared between the outer punches and the core rods and the outer diameters are sheared between the outer punches and the die plate. As the outer punches continue to extend the toroids are forced through the die plate to an exit aperture through which they are removed after the core rods'are withdrawn to a container. The toroid centers are forced through the cen tral bores in the outer punches to a different container.

In accordance with the invention, improved operability is attained by locating separate guide plates on opposite sides of the die plate and by orienting the line of the punches at an acute angle with respect to the direction of tape motion. The two guide plates maintain the two sets of punches in precise coaxial alignment, thereby increasing punch life by reducing wear and breakage. As core sizes decrease to 0.017 inch outside diameter and below the costs associated with the precision required to maintain the precise degree of alignment required to avoid punch breakage and excessive wear become prohibitive. The oppositely positioned guide plates in accordance with the invention provide an economical means of obtaining the precise alignment that is required. In addition to serving as guides, the two guide plates also serve as stripper plates to strip the cores from the inner punches and the tape from the outer punches.

By locating the line of the punches at an acute angle with respect to tape motion, punches holes can be closely spaced across the width of the ferrite tape without using expensive manufacturing procedures to mount the punches close together in their holders. In addition, different sizes of punches can be accommodated in the same holders by merely changing the acute angle to provide the proper spacing across the width of the tape.

BRIEF DESCRIPTION OF THE DRAWINGS A better understanding of the invention may be had from a consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is an enlarged partially cross-sectional and partially block diagram view of a tape press in accordance with the invention;

FIG. 2 is a plan view of an upper or core rod guide plate used in the tape press shown in FIG. 1;

FIG. 3 is a side view of the core rod plate shown in FIG. 2;

FIG. 4 is an end view of a die insert which is received by a hole in the core rod plate shown in FIGS. 2 and 3;

FIG. 5 is a sectional view of the core rod plate die insert taken along line 5-5 in the direction of the arrows as shown in FIG. 4;

FIG. 6 is a plan view of a die plate used in the tape press shown in FIG. 1;

FIG. 7 is a side view of the die plate shown in FIG.

FIG. 8 is a plan view of a lower or punch guide plate used in the tape press shown in H6. 1;

H0. 9 is a side view of the punch guide plate shown in FIG. 8;

FIG. It) is an end view of a core rod used in the tape press shown in FIG. ll;

FIG. H is a sectional view taken along line ill-Ill in the direction of the arrows of the core rod as shown in FIG. 10;

FIG. 12 is an end view of a punch used in the tape press shown in FIG. l; and

FIG. i3 is a sectional view taken along line 13-13 in the direction of the arrows of the punch as shown in FIG. 12.

DETAILED DESCRIPTIQN A punch press in accordance with the invention receives a strip of flexible ferrite tape from which toroid cores are stamped as the tape is advanced through the press along a path. The outside circumference of a core is sheared between an outer punch and the edge of a coaxially aligned die hole in a die plate. The inner circumference is sheared between an inner punch or core rod extending opposite to the outer punch and the edge of a central longitudinal bore within the outer punch. The cores are exited from the side of the die plate opposite the outer punch and the centers are exited through the central bore in the outer punch to a separate container. Guide plates on opposite sides of the die plate maintain precise coaxial alignment of the punches which may be ganged along a line forming an acute angle with the direction of tape motion. Both the inner and outer circumferences of a magnetic core may be stamped in a single punch cycle.

As shown in FIG. l, a punch press MD in accordance with the invention includes a press assembly 12 and a drive mechanism lll. Punch holders l8 and H9 slidably engage leader pins 20 and 22 on opposite sides of a die holder 24 which is mounted on the leader pins 20 and 22 in fixed relationship. As implemented herein, a set of ten core rods and 10 punches is ganged to operate with the punch holders 1%, 19 respectively as a single unit for greater efficiency. Because their mounting and operation is identical, the description of the press It]? will be made with respect to only one of each. However, it should be understood that ten of each operate in identical fashion.

A punch plate 26 is fastened to the punch holder 118 by a pair of L-shaped hold downs 28 and machine screws Bill. The punch plate 26 is generally cylindrical but has a peripheral notch 32 on the planar surface opposite the punch holder 38 for receiving the diametrically opposed hold downs 28. The punch plate 26 also has a relatively large central bore 3 3 entering from the planar surface adjacent the punch holder 1% and extending partway therethrough. A small central bore 36 extends the remainder of the way through the punch plate 26 to the planar surface opposite the punch holder 18. The small bore 36 receives the shank 38 of a core rod 40. The core rod 40 has an enlarged head 42 which rests within the large bore 34 adjacent the transition to the small bore 36. A cylindrical back-up plate 44 has a central bore extending partway therethrough shaped to receive the head 42 of the core rod 40 when the shank 38 is placed within the small bore 36 of the punch plate 26 with a force fit, thereby holding the core rod 4M) firmly in place.

An outer punch 56 is mounted in coaxial alignment with the core rod 40 on a lower punch holder 19 in a manner similar to that in which the core rod 40 is mounted on the upper punch holder 13. A cylindrical punch plate 4% is held against the punch holder 19 by a pair of L-shaped hold downs 6t) which hook over a peripheral notch in the planar surface of the punch plate 48 opposite the punch holder 119.

The punch 46: has a shank 66 terminating at one end in a transverse shearing surface 62 and at the other end in a head 64. The head 64 has a small diameter portion.

66 between the shank 60 and a large diameter portion 63. A small central bore 69 extends longitudinally all the way through the punch 46.

The punch plate 4% has a large central bore 7'!) extending partway therethrough from the planar surface adjacent the punch holder l9 and a small central bore 72 extending the remainder of the way therethrough to the planar surface opposite the punch holder 19. These bores receive the head 64 of the punch 46 with the small central bore 72 receiving the small diameter portion 68. The large diameter 66 and the large central bore 74} receiving the large diameter portion 68. The large diameter portion 68 rests against the transition of the large bore 70 to the small bore 72. A cylindrical back-up plate 74 has a large bore 76 extending partway therethrough shaped to receive the large diameter portion 68 of the punch head 64 and a smaller diameter bore 7% which communicates with the bore 62 and extends the remainder of the way therethrough. The back-up plate 74 is placed within the large bore 7% with a force tit and holds the punch firmly in place.

A die plate assembly 80 includes a cylindrical die plate 82 sandwiched between an upper or core rod guide plate 84 and a lower or punch guide plate $6. The die plate assembly 84} is mounted on the upper surface of the die holder 24 with a pair of L-shaped hold downs 88 hooked over the die plate $2. The three plates of the die plate assembly are held in exact alignment with each other by a pair of dowel rods 90 (only one being shown in FIG. l) which are placed with a force fit within bores 92 extending through all of the plates.

The plates are held in contact with each other by a pair of special bolt assemblies 94 (only one being illustrated in FIG. 1). A small bore 96 for receiving the threaded shank of a bolt extends all of the way through the die plate assembly 86. The small bore 96 has a large counter sink bore 98 which extends from the planar surface of the core rod guide plate 84 partway through the core rod guide plate 84. An intermediate sized counter sink bore MW extends from the planar surface of the outer punch guide plate $6 opposite the die plate 82 through the punch guide plate'tlu and partway into the die plate $2. A second large counter sink bore i 02 extends from the planar surface of the punch guide plate 86 opposite the die plate 82 partway through the guide plate 86. A threaded bolt MM is inserted into the bore 96 from the core rod guide plate end and the large counter sink bore 98 receives the enlarged head of the bolt 104. A nut MP6 is inserted into the bore from the opposite end with the intermediate sized counter sink bore N90 receiving a shank portion and the large counter sink bore 102 receiving an enlarged portion. The nut 106 engages the threaded bolt 104 to hold the three plates firmly together.

Ten holes or bores lltlfl (only one being shown) extend through the die plate assembly 8419, each coaxially aligned to receive a punch and core rod opposing pair. Within the die plate 02 and punch guide plate 86, the size of the bores 108 is substantially equal to the outside circumference of the cores being stamped. Within the core rod guide plate 104- the size of the bores 108 is substantially equal to the inner circumference of the cores being stamped.

The die plate 32 has a diametric exit slot or channel 110 in the planar surface adjacent the core rod guide plate 84. The channel 110 has a depth at least as great as the thickness of a core and a width sufficient to include all ten bores 108 within the channel 110. The channel 110, which is interior to the core rod guide plate 34 and the die plate 82, provides the exit for stamped cores.

The punch guide plate 86 has a diametric tape slot or channel 112 in the planar surface adjacent the die plate 82. The channel 112 provides a planar path which is interior to the die plate 82 and the punch guide plate 86 for ferrite tape as it is advanced through the tape press for stamping. The width and depth of the channel 112 must be somewhat greater than that of the ferrite tape and the width must be sufficient to include all bores 108 within the channel 112. The line of the ganged core rods 40 and punches 46 is at an acute angle chosen as 30 for this example to enable the punches holes to be closely spaced across the width of the tape without the core rods 40 and punches 46 being located inordinately close together.

The drive system for the core press 10 may be con ventional system and is represented in block diagram form as a motor 120 driving a gear box 122. The gear box 122 in turn drives a series of control cams which are mechanically coupled to operate the tape press 10. A core rod control cam 124 reciprocates the core rod 40 as required between a rest position wherein the shearing end of the core rod 40 is within the core rod guide plate 84 and an extended position wherein the shearing end extends at least to the bottom of the channel 110 and enters the central bore 69 in the punch 46.

An air blast control cam 126 is driven by the gear bos 122 and gates an air pressure source 128 at the proper times. The air pressure is directed at one end of the channel 110 and blows stamped cores out the other end where they may be caught by a suitable container not shown. A separate container for centers 130 is placed beneath the punch holder 19 and receives core centers as they are forced through the center bores 69 in the punches 46 by the core rods 40 and the air blasts.

A tape advance control cam 132 is driven by the gear box 122 and controls a tape advance mechanism 134 to successively advance ferrite tape through the channel 112.

A punch control cam 136 is driven by the gear box 122 and mechanically linked to reciprocate the punch 46 between a rest position wherein the shearing edge is within the punch guide plate 86 and below the channel 122 so that the ferrite tape can be advanced without interference and an extended position wherein the shearing edge extends at least to the bottom of the channel 110 in the die plate 82 so that stamped cores will be forced into the channel 110 to be exited. Also when extended, the punch 46 should receive the core rod 40 into the central bore 69'.

in the preferred sequence of operation, a punching cycle is initiated with the advancement of a strip of ferrite tape while the punches are in the rest position.

Then the core rod 40 is extended until the shearing edge is within the channel 1 12 slightly below the planar surface of the die plate 86 which is adjacent the punch guide plate 86. In this position the core rod 10 intersects the planar surface. Next, the punch 46 is extended until the shearing edge is substantially flush with the bottom of the core exit channel 110. As the punch 46 is extended, it engages the ferrite tape, shearing the core center between the central bore 69 and the core rod 40 and shearing the outer circumference between the punch 46 and the die plate 82. As the punch 46 continues to extend, it intersects the planar surface of the die plate 82 and the core rod 40 enters the central bore 69, forcing the core center ahead of it. The core is forced up through the die plate 82 to the exit channel 110. Then the core rod 410 is further extended, forcing the center out through the end of the central bore 69. The core rod 40 is then returned to its initial rest position with the guide plate 84 stripping the core from the core rod 40 as it is withdrawn. Next, with the shearing edge of the punch 46 remaining substantially flush with the bottom of the channel 112 to prevent the core from reentering the bore 108 in the die plate 52, a blast of air is @Tied to one end of the exit channel 110. The blast of air forces the core out the opposite end of the channel and also exerts a pressure through the central bore 69 in the punch 46 to dislodge a core which may have stuck along the path between the punch 46 and the container 130. Following removal of the cores and core centers, the punch 46 is returned to the rest position with the punch guide plate 86 stripping the ferrite tape from the shank 46 of the punch 30. The ferrite tape can now be advanced to initiate a new punching cycle.

Having described generally the construction and operation of a tape press in accordance with the invention, a specific arrangement of tape press for making 13 mil cores will now be described in greater detail. As shown in FIGS. 2 and 3, a cylindrical core rod guide plate 84 has a diameter of 1.750 inches and a thickness of 0.1 10 inch. Ten die insert receiving holes are arranged symmetrically along a diameter on centers 0.0900 inch apart. The holes 140 have a diameter of 0.0600 inch. The center line of dowel pin hole 92A lies on a diameter perpendicular to the diameter on which the holes 140 he and at a radius of 0.500 inch. The center of dowel pin hole 923 lies 0.062 inch above the perpendicular line and 0.500 inch from the diameter on which the holes 140 lie. Dowel pin holes 22A and 928 have a diameter of 0. l 560 inch and receive a dowel pin 90 (FIG. 1) having a diameter of 0.1565 inch with a force fit. The bolt holes 96 have centers which are 0.4375 inch from the diameter from which the holes 140 lie and 0.375 inch from the perpendicular diameter. The holes or bores 96 have a diameter of 0.156 inch and the counter sink bores 98 have a diameter of 0.312 inch and a depth of 0.070 inch. The core red guide plate 84 may be made of any sufficiently strong material such as a carbide C-2 steel.

A generally cylindrical die insert 142 is shown in FIGS. 4 and 5. Ten of these die inserts 142 are received by the die insert holes 140. As used in the core rod guide plate, the die insert 142 has a length of 0.110 inch and an outside diameter of 0.060150 inch and enters one of the holes 140 with a force fit of 30 pounds. A central longitudinal bore 1414 has a diameter of 0.00975 inch. The central bore 144 has a 45 chamfer 146 to a depth of 0.015 inch at the end which is at the planar surface of the core rod stripper plate 84 opposite the die plate 82. The opposite end has a peripheral channel 1 18 cut to a radial depth of 0.001 to 0.002 inch and extending 0.010 to 0.025 inch longitudinally. This channel serves as a taper to assist in the insertion of the die insert 142 into one of the holes 1140 in the core rod guide plate 84. The die insert 1412 may be made of a suitable die material such as carbide steel C-2.

As shown in FXGS. d and 7, the cylindrical die plate 82 has a diameter of 2.000 inches and a thickness of 0.110 inch. FIG. 6 is a plan view of the inner surface which abuts the core rod guide plate 8 1 when the tape press is assembled. Die insert holes 1414 are symmetrically located along a diameter with 0.0600 inch diameter holes spaced on 0.0900 inch centers. Dowel pin holes 92A and 92B are identical in size and location to those in the core rod guide plate 84. The centers of the bolt holes 96 are located the same as in the core rod guide plate 84 and have a diameter of 0.156 inch. The bores 96 are counter sunk from the planar surface which abuts the punch stripper plate 36 to a depth of 0.85 inch. This counter sink bore 100 has a diameter of 0.200 inch. A rectangular exit channel 110 is cut into the planar surface of the die plate 82 which abuts the core rod guide plate 84. A center line of the channel 110 passes through the center of the die plate 82 at an angle of with respect to the diameter on which the holes 1414 are placed. The channel 110 is 0.25 inch wide and has a depth of 0.045 inch. Because the channel 110 is oriented nearly parallel to the line of the holes 144, all of the holes 1441 fall within the channel even though the width of the channel is considerably less than the distance between the end holes 144. The die plate 82 may be made of any suitably strong material such as a C-2 carbide steel.

The ten die insert holes 144 in the die plate 82 receive 10 die inserts 142 (FIGS. 3- and 5). Each has a length of 0.72 inch and an outside diameter of- 0.060l50 inch. The central longitudinal bore 144 has a diameter of 0.01582 inch and the end which is placed near the planar surface of the die plate 82 which abuts the punch stripper plate 86 has a peripheral groove 148 with a radial depth of 0.0001 to 0.0002 inch and a longitudinal depth of0.010 to 0.025 inch. The groove 148 makes it easier to insert the 10 die inserts 142 into the 10 holes 144 with a force fit of 30 pounds.

As shown in FlGS. and 9, the punch guide plate 86 has a diameter of 1.750 inches and a thickness of 0.10 inch. it has ten holes 150 of a size and location identical to the holes 1441 and 11410 for receiving the punch 46. The dowel pin holes 92A and 92B also have a size and location identical to those in the core rod guide plate 84 and die plate 82. The intermediate counter sink bores 100 in the die plate 82 are concentric with large counter sink bores 1102 which have a diameter of 0.312 inch and enter the punch guide plate 86 to a depth of 0.085 inch from the planar surface of the punch guide plate 86 opposite the die plate 82. A rectangular ferrite tape receiving channel 1121s cut into the punch guide plate 86 on a center line passing through the center of the guide plate 86. The channel 112 has a width of 0.7000 inch and a depth of 0.010 inch. The center line of the channel 112 lies at an angle of 30 with respect made of a suitably strong material such as a C-2 carbide steel.

The ten die insert holes in the punch guide plate 86 receive then of the die inserts 1142 (F168. 4 and 5). Each has a length of 0.072 inch and an outside diame ter of 0.060150 inch. The central longitudinal bore 1441 has a diameter of 0.01582 inch and a 45 chamfer 1 16 to a depth of 0.010 to 0.015 inch at an end which is placed adjacent the planar surface of the punch guide plate 86 which is opposite the die plate 82. At the opposite end of the die insert 1412, the peripheral groove 148 has a radial depth of 0.0001 to 0.0002 inch and a longitudinal depth of 0.010 to 0.025 inch. This peripheral groove makes it easier to insert the 10 die inserts 1142 into the holes 150 in the punch guide plate 86 with a force fit of 30 pounds.

As shown in FIGS. 10am! 11, the core rod 410 has a shank 38 connected to a head 42. The shank has a diameter of 0.01360 inch and the head 42 has a diameter of 0.073 inch. The overall length of the core rod 40 is 0.985 inch and the length of the head portion 42 is 0.185 inch. The core rod 410 may be made of any suitably hard material such as C-2 carbide steel.

As shown in FIGS. 12 and 13, the punch 46 has a shank 60 connected to a head 64. The shank 60 has a length of 0.35 inch and an outside diameter of 0.01572 inch. A central bore 6? through the punch 46 has a diameter of 0.00975 inch to a depth of 0.100 inch from the shearing end 156 and a diameter of 0.01015 inch throughout the remainder of the shaft. The head 64 has a large diameter of 0.124 inch truncated by parallel planes spaced 0.074 inch apart. A smaller diameter portion having a diameter of 0.0550 inch receives the shank 60 through a central bore having a diameter the same as the diameter of the shaft 160. The enlarged portion of the punch 36 has a central bore of diameter 0.0130 inch extending therethrough and communicating with the central bore 169 in the shaft 160. The enlarged portion 68 of the head 64 has a depth of 0.0620 inch. The punch 46 may be made of any suitably hard material such as (3-2 carbide steel.

Although there has been described above a specific arrangement of a tape press in accordance with the invention for the purpose of illustrating the manner in which the invention may be used to advantage, it will be appreciated that the invention is not limited thereto. Accordingly, any and all modifications, variations or equivalent arrangements which may occur to those skilled in the art should be considered to be within the scope of the invention.

I claim:

1. A tape press for stamping toroidal cores from a ferrite tape comprising:

a plurality of parallel core rods having shearing ends positioned along a line, the core rods being perpendicular to a given plane and spaced apart along the line with each adjacent pair of core rods being spaced by a distance sufficient to permit a die plate to have a plurality of holes therein with each hole being coaxially aligned with a different core rod and with each hole having a sufficiently large diameter to receive a die insert, and the line being parallel to and spaced apart from the given plane on one side thereof;

means couples to the core rods for reciprocating the core rods in a direction normal to the given plane between a first position in which the shearing ends are along the line and a second position in which the core rods intersect the given plane;

a plurality of outer punches having shearing ends, each positioned opposite to and somewhat spaced apart from a core rod on the opposite side of the given plane, each punch having a central longitudinal bore in coaxial alignment with the opposing core rod;

a die plate positioned between the core rods and punches with one surface along the given plane, the die plate having a plurality of holes therethrough, each hole being coaxially aligned with a different outer punch and having a diameter sufficiently large to receive a die insert;

a plurality of die inserts, each disposed within a different one of the plurality of holes through the die plate, each die insert having a central bore coaxially aligned to receive a different outer punch when inserted in a die plate hole;

means for advancing the ferrite tape in a tape plane adjacent to and parallel to the given plane on the same side thereof as the outer punches, the direction of advancement forming an acute angle with respect to the line of the core rods which substantially decreases the spacing between punched holes in the ferrite tape in a direction perpendicular to the direction of tape advancement with respect to the spacing between outer punches in a direction along the line of the core rods; and

means coupled to the outer punches for reciprocating the outer punches in a direction normal to the given plane between a first position in which the shearing ends are adjacent the tape plane on the opposite side thereof from the given plane and a second position in which the outer punches intersect the given plane.

2. A tape press for stamping toroidal cores from a ferrite tape comprising:

a plurality of parallel core rods having shearing ends positioned along a line, the core rods being perpendicular to a given plane and the line being parallel to and spaced apart from the given plane on'one side thereof;

means coupled to the core rods for'reciprocating the core rods in a direction normal to the given plane between a first position in which the shearing ends are along the line and a second position in which the core rods intersect the given plane;

a plurality of outer punches having shearing ends, each positioned opposite to and somewhat spaced apart from a core rod on the opposite side of the given plane, each punch having a central longitudinal bore in coaxial alignment with the opposing core rod;

a die plate positioned between the core rods and punches with one surface along the given plane, the die plate having a plurality of holes therethrough, each hole being coaxially aligned to receive a different outer punch;

means for advancing the ferrite tape in a tape plane adjacent to and parallel to the given plane on the same side thereof as the outer punches, the direction of advancement forming an acute angle with respect to the line of the core rods;

first and second guide plates positioned on opposite sides ofthe die plate and in abutment therewith, the first and second guide plates having a plurality of holes therethrough coaxially aligned to receive and guide the core rods and outer punches respec tively in mating relationship, the first guide plate and the die plate forming a core exiting aperture and the second guide plate and the die plate forming an interior tape guide aperture in the tape plane; and

means coupled to the outer punches for reciprocating the outer punches in a direction normal to the given plane between a first position in which the shearing ends are adjacent the tape plane on the opposite side thereof from the given plane and a second position in which the outer punches intersect the given plane.

3. For use in a ferrite tape press having a plurality of parallel core rods positioned along a line and a plurality of opposing punches positioned along the same line, each having a central longitudinal bore for receiving a different opposed core rod in an intermediate core punching zone, a die plate assembly comprising a die plate and a pair of parallel guide plates positioned on opposite sides of the die plate in the core punching zone between said core rods and punches, said die plate assembly having a plurality of holes extending therethrough for receiving the core rods from a first side and the punches from a second side, and including interior apertures defining a tape slot having a longitudinal axis positioned near and parallel to said second side and a spaced apart core exit slot having a longitudinal axis positioned near and parallel to said first side, said tape and exit slots each communicating with all of the holes in the die plate assembly.

4. The invention as set forth in claim 3 above, wherein the longitudinal axis of the tape slot forms an acute angle with respect to the line of the core rods,

5. Apparatus for stamping toroidal cores having an outer circumference and an inner circumference comprising:

a die plate having a shearing surface lying in a given plane and having an aperture therethrough normal to the given plane and coaxial with a punch central axis;

a core rod positioned on the central axis in alignment with the aperture in the die plate on the opposite side of the die plate from the shearing surface, the core rod having a terminal shearing edge adjacent the die plate and defining the inner circumference of the core;

a first guide plate positioned normal to the central axis and adjacent the side of the die plate having a shearing surface, said first guide plate having a hole therethrough coaxial with the central axis of a size suitable for receiving and guiding the core rod;

an outer punch having a central longitudinal bore therethrough positioned coaxially with the central axis on the side of the die plate having the shearing surface, the outer punch having a shearing edge adjacent the die plate;

a second guide plate positioned normal to the central axis and adjacent the side of the die plate having the shearing surface, the second guide plate having a hole therethrough coaxial with the central axis for receiving and guiding the outer punch;

means for holding the die plate, first guide plate and second guide plate in contact and in exact aligment with each other to form a high precision die plate assembly, the holding means including at least one rod extending through the die plate and first and second guide plates of the die plate assembly;

means coupled to the core rod and the outer punch for moving the core rod and the outer punch towards each other along the central axis; and

means for positioning a web member between the side of the die plate having a shearing surface and the outer punch parallel to the given plane, such that the web member is sheared between the shearing edge of the outer punch and the shearing surface of the die plate to form an outer circumference as the outer punch enters the aperture in the die plate and is sheared between the shearing edge of the core rod and the shearing edge of the outer punch to form an inner circumference as the core rod enters the bore in the outer punch. 6. The invention as set forth in claim above, wherein the outer punch has a cylindrical outer circumference with a diameter of less than 0.017 inch.

7. The invention as set forth in claim 6 above, wherein the cylindrical outer circumference of the punch has a diameter of 0.013 inch or less.

8. A punch and die set for stamping toroids from a web member comprising:

a die plate assembly including a first guide plate, a second guide plate and a die plate positioned along a given plane between the first and second guide plates, the first guide plate having at least one bore therethrough substantially equal in diameter to the inside diameter of the toroid being stamped, and the die plate and second guide plate each having at least one bore therethrough substantially equal in diameter to the outside diameter of the toroid being stamped, the at least one bore in each plate being concentric with an associated individual central axis, said die plate assembly defining a tape slot for receiving a web member extending through the die plate assembly transverse to the central axis at the juncture of the die plate and the second guide plate and also defining an exit slot for removal of toroids extending through the die plate assembly transverse to the central axis at the juncture of the first guide plate and the die plate, said exit and tape slots each having a proper size and location to allow the central axis to extend therethrough; at least one core rod mounted concentric with the central axis with a shearing end extending into the bore in the first guide plate and reciprocating between an outer position within the first guide plate and an inner position wherein the shearing end registers within an outer punch and extends at least to a surface of the exit slot adjacent the die plate;

means for reciprocating the core rod between the inner and outer positions; at least one outer punch mounted concentric with the central axis have a longitudinal bore therethrough for receiving a toroid center and said core rod, said outer punch having a shearingend mounted to reciprocate within the bores in the die plate and second guide plate between an outer position within the second guide plate and an inner position in which the shearing end extends at least to said surface of the exit slot adjacent the die plate; and

means for reciprocating the outer punch between the inner and outer positions.

9. A press for stamping a toroid having inner and outer circumferences from a web member comprising:

a die plate having first and second spaced apart sides and including at least one hole in concentric alignment with at least one central axis extending therebetween for receiving an outer punch, said hole having a cross section corresponding in size and shape to the outer circumference of the toroid being stamped;

a first guide plate having first and second spaced apart sides, the second side having a channel therein, there being at least one guide hole in concentric alignment with the central axis for receiving a core rod extending between the first side and the channel in the second side, said guide hole having a cross section corresponding to the size and shape of the inner circumference of the toroid being stamped, the second side of the first guide plate being disposed in abutment with the first side of the die plate;

a second guide plate having first and second spaced apart sides, the first side having a channel therein for receiving a web member, there being at least one guide hole in concentric alignment with the central axis for receiving an outer punch extending between the channel in the first side and the second side, the hole having a cross section corresponding to the size and shape of the outer circumference of the toroid being stamped, the first side of the second guide plate being disposed in abutment with the second side of the die plate;

at least one core rod mounted adjacent the first side of the first guide plate in concentric alignment with the central axis and having a shearing end, said core rod having a cross section corresponding in size and shape to the inner circumference of the toroid, the shearing end of the core rod being disposed within the hole in the first guide plate;

means for reciprocally moving the inner punch along the line of the central axis between a first position in which the shearing end is between the first side and the channel of the first guide plate and a sec ond position in which the shearing end extends at least to the first surface of the die plate;

at least one outer punch having a central axis, a shearing end and a central longitudinal bore mounted adjacent the second side of the second guide plate in concentric alignment with the central axis, said outer punch having inner and outer cross sections corresponding in size and shape to the inner and outer circumferences respectively of the toroid, the outer punch having the shearing end thereof disposed within the hole in the second guide plate;

means for reciprocally moving the outer punch along the line of the central axis between a first position in which the shearing edge is between the channel and second side of the second guide plate and a second position in which the shearing edge extends at least to the first edge of the die plate;

means for exerting a fluid pressure at one end of the channel in the first guide plate to force cores therethrough; and

means for successively advancing the web member through the channel in the second guide plate.

10. A ferrite tape press comprising:

a plurality of first cylindrical punches positioned along a first line;

plurality of second cylindrical punches positioned along a second line parallel to the first line, each having an outside diameter larger than the diameter of the first cylindrical punches, each having a longitudinal concentric bore of substantially the same diameter as the first punches, and each being disposed opposite a different first punch with the central bore aligned to receive the opposed first punch;

cylindrical first guide plate having a longitudinal central axis and a flat reference surface perpendicular thereto, said first guide plate having therein a plurality of holes therein for receiving a die insert; plurality of first guide plate inserts, each located within a different hole within the first guide plate and each including a central bore parallel to the longitudinal central axis of the first guide plate of a size substantially the same as the first cylindrical punches, each insert receiving a first punch from an end opposite the reference plane in mating and guiding relation;

cylindrical die plate having an upper flat surface disposed adjacent the reference surface of the first guide plate and a lower flat surface spaced apart from and parallel to the upper flat surface, said die plate having a plurality of holes therein aligned with the holes in the first guide plate, said die plate and first guide plate defining an exit slot at the juncture of the upper die plate surface and the first guide plate reference surface with a width and orientation allowing all of the holes in the first guide plate inserts to communicate with the exit slot; plurality of die inserts, each located within a different die plate hole and each having a central bore with a diameter substantially equal to the outside diameter of the second punches for receiving the second punches in guiding and mating relation; second guide plate having a flat upper surface disposed adjacent the lower surface of the die plate and a flat lower surface parallel to and spaced apart therefrom, said second guide plate having a plural ity of holes therein aligned with the holes in the die plate and first guide plate, said second guide plate and die plate defining a tape slot having a longitudinal axis at the juncture of the lower surface of the die plate and the upper surface of the second guide plate, said longitudinal axis being at an acute angle with respect to a plane extending between the first and second lines, said tape slot having a width and orientation which allows all of the holes in the die plate inserts to communicate with the tape slot;

a plurality of second guide plate inserts, each located within a different second guide plate hole, each having a central bore with a diameter substantially equal to the outside diameter of the second punches and each receiving a second punch from an end adjacent the lower surface in guiding and mating relation;

means coupled to said first and second punches for driving and first and second punches with cyclic reciprocating motion such that during the course of a cycle the first punches first descend to a position proximate the upper surface of a strip of ferrite tape, the second punches then ascend to a point proximate the exit slot, the central bores in the second punches receiving the first punches and sheared off central disks of ferrite material as the second punches ascend, said second punches pushing a sheared off toroid of ferrite material ahead of them, the first punches then return to their starting position with the ferrite toroid being stripped off against the lower reference surface of the second guide plate, and then the second punches return to their starting position;

means providing a blast of air to blow ferrite toroids out of the exit slot between the time the first punches return to their starting position and the time the second punches return to their starting position; and

means for advancing ferrite tape through said tape slot along the longitudinal direction between the time the lower punches return to their starting position and the start of a new punching cycle 11. The invention as set forth in claim 10 above,

wherein the acute angle which the longitudinal axis of the tape slot forms with the plane extending between the first and second lines is 30. 

1. A tape press for stamping toroidal cores from a ferrite tape comprising: a plurality of parallel core rods having shearing ends positioned along a line, the core rods being perpendicular to a given plane and spaced apart along the line with each adjacent pair of core rods being spaced by a distance sufficient to permit a die plate to have a plurality of holes therein with each hole being coaxially aligned with a different core rod and with each hole having a sufficiently large diameter to receive a die insert, and the line being parallel to and spaced apart from the given plane on one side thereof; means couples to the core rods for reciprocating the core rods in a direction normal to the given plane between a first position in which the shearing ends are along the line and a second position in which the core rods intersect the given plane; a plurality of outer punches having shearing ends, each positioned opposite to and somewhat spaced apart from a core rod on the opposite side of the given plane, each punch having a central longitudinal bore in coaxial alignment with the opposing core rod; a die plate positioned between the core rods and punches with one surface along the given plane, the die plate having a plurality of holes therethrough, each hole being coaxially aligned with a different outer punch and having a diameter sufficiently large to receive a die insert; a plurality of die inserts, each disposed within a different one of the plurality of holes through the die plate, each die insert having a central bore coaxially aligned to receive a different outer punch when inserted in a die plate hole; means for advancing the ferrite tape in a tape plane adjacent to and parallel to the given plane on the same side thereof as the outer punches, the direction of advancement forming an acute angle with respect to the line of the core rods which substantially decreases the spacing between punched holes in the ferrite tape in a direction perpendicular to the direction of tape advancement with respect to the spacing between outer punches in a direction along the line of the core rods; and means coupled to the outer punches for reciprocating the outer punches in a direction normal to the given plane between a first position in which the shearing ends are adjacent the tape plane on the opposite side thereof from the given plane and a second position in which the outer punches intersect the given plane.
 2. A tape press for stamping toroidal cores from a ferrite tape comprising: a plurality of parallel core rods having shearing ends positioned along a line, the core rods being perpendicular to a given plane and the line being parallel to and spaced apart from the given plane on one side thereof; means coupled to the core rods for reciprocating the core rods in a direction normal to the given plane between a first position in which the shearing ends are along the line and a second position in which the core rods intersect the given plane; a plurality of outer punches having shearing ends, each positioned opposite to and somewhat spaced apart from a core rod on the opposite side of the given plane, each punch having a central longitudinal bore in coaxial alignment with the opposing core rod; a die plate positioned between the core rods and punches with one surface along the given plane, the die plate having a plurality of holes therethrough, each hole being coaxially aligned to receive a different outer punch; means for advancing the ferrite tape in a tape plane adjacent to and parallel to the given plane on the same side thereof as the outer punches, the direction of advancement forming an acute angle with respect to the line of the core rods; first and second guide plates positioned on opposite sides of the die plate and in abutment therewith, the first and second guide plates having a plurality of holes therethrough coaxially aligned to receive and guide the core rods and outer punches respectively in mating relationship, the first guide plate and the die plate forming a core exiting aperture and the second guide plate and the die plate forming an interior tape guide aperture in the tape plane; and means coupled to the outer punches for reciprocating the outer punches in a direction normal to the given plane between a first position in which the shearing ends are adjacent the tape plane on the opposite side thereof from the given plane and a second position in which the outer punches intersect the given plane.
 3. For use in a ferrite tape press having a plurality of parallel core rods positioned along a line and a plurality of opposing punches positioned along the same line, each having a central longitudinal bore for receiving a different opposed core rod in an intermediate core punching zone, a die plate assembly comprising a die plate and a pair of parallel guide plates positioned on opposite sides of the die plate in the core punching zone between said core rods and punches, said die plate assembly having a plurality of holes extending therethrough for receiving the core rods from a first side and the punches from a second side, and including interior apertures defining a tape slot having a longitudinal axis positioned near and parallel to said second side and a spaced apart core exit slot having a longitudinal axis positioned near and parallel to said first side, said tape and exit slots each communicating with all of the holes in the die plate assembly.
 4. The invention as set forth in claim 3 above, wherein the longitudinal axis of the tape slot forms an acute angle with respect to the line of the core rods.
 5. Apparatus for stamping toroidal cores having an outer circumference and an inner circumference comprising: a die plate having a shearing surface lying in a given plane and having an aperture therethrough normal to the given plane and coaxial with a punch central axis; a core rod positioned on the central axis in alignment with the aperture in the die plate on the opposite side of the die plate from the shearing surface, the core rod having a terminal shearing edge adjacent the die plate and defining the inner circumference of the core; a first guide plate positioned normal to the central axis and adjacent the side of the die plate having a shearing surface, said first guide plate having a hole therethrough coaxial with the central axis of a size suitable for receiving and guiding the core rod; an outer punch having a central longitudinal bore therethrough positioned coaxially with the central axis on the side of the die plate having the shearing surface, the outer punch having a shearing edge adjacent the die plate; a second guide plate positioned normal to the central axis and adjacent the side of the die plate having the shearing surface, the second guide plate having a hole therethrough coaxial with the central axis for receiving and guiding the outer punch; means for holding the die plate, first guide plate and second guide plate in contact and in exact aligment with each other to form a high precision die plate assembly, the holding means including at least one rod extending through the die plate and first and second guide plates of the die plate assembly; means coupled to the core rod and the outer punch for moving the core rod and the outer punch towaRds each other along the central axis; and means for positioning a web member between the side of the die plate having a shearing surface and the outer punch parallel to the given plane, such that the web member is sheared between the shearing edge of the outer punch and the shearing surface of the die plate to form an outer circumference as the outer punch enters the aperture in the die plate and is sheared between the shearing edge of the core rod and the shearing edge of the outer punch to form an inner circumference as the core rod enters the bore in the outer punch.
 6. The invention as set forth in claim 5 above, wherein the outer punch has a cylindrical outer circumference with a diameter of less than 0.017 inch.
 7. The invention as set forth in claim 6 above, wherein the cylindrical outer circumference of the punch has a diameter of 0.013 inch or less.
 8. A punch and die set for stamping toroids from a web member comprising: a die plate assembly including a first guide plate, a second guide plate and a die plate positioned along a given plane between the first and second guide plates, the first guide plate having at least one bore therethrough substantially equal in diameter to the inside diameter of the toroid being stamped, and the die plate and second guide plate each having at least one bore therethrough substantially equal in diameter to the outside diameter of the toroid being stamped, the at least one bore in each plate being concentric with an associated individual central axis, said die plate assembly defining a tape slot for receiving a web member extending through the die plate assembly transverse to the central axis at the juncture of the die plate and the second guide plate and also defining an exit slot for removal of toroids extending through the die plate assembly transverse to the central axis at the juncture of the first guide plate and the die plate, said exit and tape slots each having a proper size and location to allow the central axis to extend therethrough; at least one core rod mounted concentric with the central axis with a shearing end extending into the bore in the first guide plate and reciprocating between an outer position within the first guide plate and an inner position wherein the shearing end registers within an outer punch and extends at least to a surface of the exit slot adjacent the die plate; means for reciprocating the core rod between the inner and outer positions; at least one outer punch mounted concentric with the central axis have a longitudinal bore therethrough for receiving a toroid center and said core rod, said outer punch having a shearing end mounted to reciprocate within the bores in the die plate and second guide plate between an outer position within the second guide plate and an inner position in which the shearing end extends at least to said surface of the exit slot adjacent the die plate; and means for reciprocating the outer punch between the inner and outer positions.
 9. A press for stamping a toroid having inner and outer circumferences from a web member comprising: a die plate having first and second spaced apart sides and including at least one hole in concentric alignment with at least one central axis extending therebetween for receiving an outer punch, said hole having a cross section corresponding in size and shape to the outer circumference of the toroid being stamped; a first guide plate having first and second spaced apart sides, the second side having a channel therein, there being at least one guide hole in concentric alignment with the central axis for receiving a core rod extending between the first side and the channel in the second side, said guide hole having a cross section corresponding to the size and shape of the inner circumference of the toroid being stamped, the second side of the first guide plate being disposed in abutment with the first side of the die plate; a second guide plate having first and second sPaced apart sides, the first side having a channel therein for receiving a web member, there being at least one guide hole in concentric alignment with the central axis for receiving an outer punch extending between the channel in the first side and the second side, the hole having a cross section corresponding to the size and shape of the outer circumference of the toroid being stamped, the first side of the second guide plate being disposed in abutment with the second side of the die plate; at least one core rod mounted adjacent the first side of the first guide plate in concentric alignment with the central axis and having a shearing end, said core rod having a cross section corresponding in size and shape to the inner circumference of the toroid, the shearing end of the core rod being disposed within the hole in the first guide plate; means for reciprocally moving the inner punch along the line of the central axis between a first position in which the shearing end is between the first side and the channel of the first guide plate and a second position in which the shearing end extends at least to the first surface of the die plate; at least one outer punch having a central axis, a shearing end and a central longitudinal bore mounted adjacent the second side of the second guide plate in concentric alignment with the central axis, said outer punch having inner and outer cross sections corresponding in size and shape to the inner and outer circumferences respectively of the toroid, the outer punch having the shearing end thereof disposed within the hole in the second guide plate; means for reciprocally moving the outer punch along the line of the central axis between a first position in which the shearing edge is between the channel and second side of the second guide plate and a second position in which the shearing edge extends at least to the first edge of the die plate; means for exerting a fluid pressure at one end of the channel in the first guide plate to force cores therethrough; and means for successively advancing the web member through the channel in the second guide plate.
 10. A ferrite tape press comprising: a plurality of first cylindrical punches positioned along a first line; a plurality of second cylindrical punches positioned along a second line parallel to the first line, each having an outside diameter larger than the diameter of the first cylindrical punches, each having a longitudinal concentric bore of substantially the same diameter as the first punches, and each being disposed opposite a different first punch with the central bore aligned to receive the opposed first punch; a cylindrical first guide plate having a longitudinal central axis and a flat reference surface perpendicular thereto, said first guide plate having therein a plurality of holes therein for receiving a die insert; a plurality of first guide plate inserts, each located within a different hole within the first guide plate and each including a central bore parallel to the longitudinal central axis of the first guide plate of a size substantially the same as the first cylindrical punches, each insert receiving a first punch from an end opposite the reference plane in mating and guiding relation; a cylindrical die plate having an upper flat surface disposed adjacent the reference surface of the first guide plate and a lower flat surface spaced apart from and parallel to the upper flat surface, said die plate having a plurality of holes therein aligned with the holes in the first guide plate, said die plate and first guide plate defining an exit slot at the juncture of the upper die plate surface and the first guide plate reference surface with a width and orientation allowing all of the holes in the first guide plate inserts to communicate with the exit slot; a plurality of die inserts, each located within a different die plate hole and each having a central bore with a diameter substantially equal to the outside diameter Of the second punches for receiving the second punches in guiding and mating relation; a second guide plate having a flat upper surface disposed adjacent the lower surface of the die plate and a flat lower surface parallel to and spaced apart therefrom, said second guide plate having a plurality of holes therein aligned with the holes in the die plate and first guide plate, said second guide plate and die plate defining a tape slot having a longitudinal axis at the juncture of the lower surface of the die plate and the upper surface of the second guide plate, said longitudinal axis being at an acute angle with respect to a plane extending between the first and second lines, said tape slot having a width and orientation which allows all of the holes in the die plate inserts to communicate with the tape slot; a plurality of second guide plate inserts, each located within a different second guide plate hole, each having a central bore with a diameter substantially equal to the outside diameter of the second punches and each receiving a second punch from an end adjacent the lower surface in guiding and mating relation; means coupled to said first and second punches for driving and first and second punches with cyclic reciprocating motion such that during the course of a cycle the first punches first descend to a position proximate the upper surface of a strip of ferrite tape, the second punches then ascend to a point proximate the exit slot, the central bores in the second punches receiving the first punches and sheared off central disks of ferrite material as the second punches ascend, said second punches pushing a sheared off toroid of ferrite material ahead of them, the first punches then return to their starting position with the ferrite toroid being stripped off against the lower reference surface of the second guide plate, and then the second punches return to their starting position; means providing a blast of air to blow ferrite toroids out of the exit slot between the time the first punches return to their starting position and the time the second punches return to their starting position; and means for advancing ferrite tape through said tape slot along the longitudinal direction between the time the lower punches return to their starting position and the start of a new punching cycle.
 11. The invention as set forth in claim 10 above, wherein the acute angle which the longitudinal axis of the tape slot forms with the plane extending between the first and second lines is 30*. 